Finding how many times unique strings occurs within a string

Question

say for example i am given a string: String s= "AA BB CC AA BB CC DD DD FF EE FF AA", and i would want to know how many times each token (i.e "AA", "BB", "CC", "DD", "EE", "FF") occurs. (so in this "AA" occurs 3 times, "BB" occurs 2 time, "CC" occurs twice, "EE" once, etc). how would i go about doing this?
what i have so far is incomplete:
public void getOccurances(String s) {
String triple="";
StringTokenizer st = new StringTokenizer(s);
numOfTriples=st.countTokens();
while (st.hasMoreTokens()) {
triple=st.nextToken();
any help would be greatly appreciated .

Answer 1

any other ways without using arrays?Use a Map keyed by String (your tokens), and containing Integer objects representing the number of occurences.
I.e.:
Map occurenceCount = new HashMap();
// for each token myNewToken
if (occurenceCount.containsKey(myNewToken)) {
  int currentNumOccurences = ((Integer) occurenceCount.get(myNewToken)).intValue();
  occurenceCount.put(myNewToken, new Integer(currentNumOccurences + 1));
else {
  occurenceCount.put(myNewToken, new Integer(1));
}To display the associative array just use occurenceCount.toString()Linda